Press Association: The Prince of Wales and the Duchess of Cornwall have begun their 10-day tour of South America with the issue of climate change at the top of their agenda. Charles and Camilla arrived in Chile for the official visit that will also take them to Brazil, Ecuador and the Galapagos Islands. Highlighting the issue of global warming is a major theme of the tour and later this week the Prince will give a dire climate change warning to the world. The heir to the throne will tell …